Rehabilitating an attrited language in a bilingual person with aphasia.

Language difficulties can arise from reduced exposure to any given language (e.g. attrition) or after brain damage (e.g. aphasia). The manifestations of attrition and aphasia are often similar so differentiating between their effects on language loss and recovery is challenging. We investigated treatment effects for an English-Hebrew bilingual person with stroke-induced aphasia who had minimal contact with his Hebrew for over 14 years. We asked whether his attrited language could be rehabilitated, how effects of attrition and aphasia can be dissociated, and how such dissociation aids our understanding of the mechanisms involved in language recovery in aphasia. We administered a verb-based semantic treatment in Hebrew three times a week for six weeks (totalling 29 hours of therapy) and assessed changes in both Hebrew and English comprehension and production abilities across a variety of language tasks. Quantitative analyses demonstrated improvement in Hebrew production across language tasks, including those involving lexical retrieval processes that were trained during treatment. Improvement to English occurred in these same lexical retrieval tasks only. We interpret these results as indicating that the participant's attrited language (Hebrew) could be rehabilitated with both specific treatment and general exposure to Hebrew contributing to improvement. Furthermore, treatment effects transferred to the untreated English. Qualitative analyses indicated that an interaction among aphasia, incomplete mastery of Hebrew pre-stroke, and attrition contributed to the participant's language difficulties post-stroke. We conclude that partially shared underlying mechanisms of attrition and aphasia drive language processing and changes to it with treatment.

Semantic and lexical features of words dissimilarly affected by non-fluent, logopenic, and semantic primary progressive aphasia.

OBJECTIVE: To determine the effect of three psycholinguistic variables-lexical frequency, age of acquisition (AoA), and neighborhood density (ND)-on lexical-semantic processing in individuals with non-fluent (nfvPPA), logopenic (lvPPA), and semantic primary progressive aphasia (svPPA). Identifying the scope and independence of these features can provide valuable information about the organization of words in our mind and brain. METHOD: We administered a lexical decision task-with words carefully selected to permit distinguishing lexical frequency, AoA, and orthographic ND effects-to 41 individuals with PPA (13 nfvPPA, 14 lvPPA, 14 svPPA) and 25 controls. RESULTS: Of the psycholinguistic variables studied, lexical frequency had the largest influence on lexical-semantic processing, but AoA and ND also played an independent role. The results reflect a brain-language relationship with different proportional effects of frequency, AoA, and ND in the PPA variants, in a pattern that is consistent with the organization of the mental lexicon. Individuals with nfvPPA and lvPPA experienced an ND effect consistent with the role of inferior frontal and temporoparietal regions in lexical analysis and word form processing. By contrast, individuals with svPPA experienced an AoA effect consistent with the role of the anterior temporal lobe in semantic processing. CONCLUSIONS: The findings are in line with a hierarchical mental lexicon structure with a conceptual (semantic) and a lexeme (word-form) level, such that a selective deficit at one of these levels of the mental lexicon manifests differently in lexical-semantic processing performance, consistent with the affected language-specific brain region in each PPA variant.

The Role of Executive Functions in Object- and Action-Naming among Older Adults.

Background/Study Context: Lexical retrieval abilities and executive function skills decline with age. The extent to which these processes might be interdependent remains unknown. The aim of the current study was to examine whether individual differences in three executive functions (shifting, fluency, and inhibition) predicted naming performance in older adults. Methods: The sample included 264 adults aged 55-84. Six measures of executive functions were combined to make three executive function composites scores. Lexical retrieval performance was measured by accuracy and response time on two tasks: object naming and action naming. We conducted a series of multiple regressions to test whether executive function performance predicts naming abilities in older adults. Results: We found that different executive functions predicted naming speed and accuracy. Shifting predicted naming accuracy for both object and action naming while fluency predicted response times on both tests as well as object naming accuracy, after controlling for education, gender, age, working memory span, and speed of processing in all regressions. Interestingly, inhibition did not contribute to naming accuracy or response times on either task. Conclusion: The findings support the notion that preservation of some executive functions contributes to successful naming in older adults and that different executive functions are associated with naming speed and accuracy.

Levels of Abstractness in Semantic Noun and Verb Processing: The Role of Sensory-Perceptual and Sensory-Motor Information.

Effects of concreteness and grammatical class on lexical-semantic processing are well-documented, but the role of sensory-perceptual and sensory-motor features of concepts in underlying mechanisms producing these effects is relatively unknown. We hypothesized that processing dissimilarities in accuracy and response time performance in nouns versus verbs, concrete versus abstract words, and their interaction can be explained by differences in semantic weight-the combined amount of sensory-perceptual and sensory-motor information to conceptual representations-across those grammatical and semantic categories. We assessed performance on concrete and abstract subcategories of nouns and verbs with a semantic similarity judgment task. Results showed that when main effects of concreteness and grammatical class were analyzed in more detail, the grammatical-class effect, in which nouns are processed more accurately and quicker than verbs, was only present for concrete words, not for their abstract counterparts. Moreover, the concreteness effect, measured at different levels of abstract words, was present for both nouns and verbs, but it was less pronounced for verbs. The results do not support the grammatical-class hypothesis, in which nouns and verbs are separately organized, and instead provide evidence in favor of a unitary semantic space, in which lexical-semantic processing is influenced by the beneficial effect of sensory-perceptual and sensory-motor information of concepts.

Effects of metabolic syndrome on language functions in aging.

This study explored effects of the metabolic syndrome (MetS) on language in aging. MetS is a constellation of five vascular and metabolic risk factors associated with the development of chronic diseases and increased risk of mortality, as well as brain and cognitive impairments. We tested 281 English-speaking older adults aged 55-84, free of stroke and dementia. Presence of MetS was based on the harmonized criteria (Alberti et al., 2009). Language performance was assessed by measures of accuracy and reaction time on two tasks of lexical retrieval and two tasks of sentence processing. Regression analyses, adjusted for age, education, gender, diabetes, hypertension, and heart disease, demonstrated that participants with MetS had significantly lower accuracy on measures of lexical retrieval (action naming) and sentence processing (embedded sentences, both subject and object relative clauses). Reaction time was slightly faster on the test of embedded sentences among those with MetS. MetS adversely affects the language performance of older adults, impairing accuracy of both lexical retrieval and sentence processing. This finding reinforces and extends results of earlier research documenting the negative influence of potentially treatable medical conditions (diabetes, hypertension) on language performance in aging. The unanticipated finding that persons with MetS were faster in processing embedded sentences may represent an impairment of timing functions among older individuals with MetS.

The effect of plausibility on sentence comprehension among older adults and its relation to cognitive functions.

UNLABELLED: BACKGROUND/STUDY CONTEXT: Older adults show age-related decline in complex-sentence comprehension. This has been attributed to a decrease in cognitive abilities that may support language processing, such as working memory (e.g., Caplan, DeDe, Waters, & Michaud, 2011,Psychology and Aging, 26, 439-450). The authors examined whether older adults have difficulty comprehending semantically implausible sentences and whether specific executive functions contribute to their comprehension performance. METHODS: Forty-two younger adults (aged 18-35) and 42 older adults (aged 55-75) were tested on two experimental tasks: a multiple negative comprehension task and an information processing battery. RESULTS: Both groups, older and younger adults, showed poorer performance for implausible sentences than for plausible sentences; however, no interaction was found between plausibility and age group. A regression analysis revealed that inhibition efficiency, as measured by a task that required resistance to proactive interference, predicted comprehension of implausible sentences in older adults only. Consistent with the compensation hypothesis, the older adults with better inhibition skills showed better comprehension than those with poor inhibition skills. CONCLUSION: The findings suggest that semantic implausibility, along with syntactic complexity, increases linguistic and cognitive processing loads on auditory sentence comprehension. Moreover, the contribution of inhibitory control to the processing of semantic plausibility, particularly among older adults, suggests that the relationship between cognitive ability and language comprehension is strongly influenced by age.

Hemispheric processing of vocal emblem sounds.

Vocal emblems, such as shh and brr, are speech sounds that have linguistic and nonlinguistic features; thus, it is unclear how they are processed in the brain. Five adult dextral individuals with left-brain damage and moderate-severe Wernicke's aphasia, five adult dextral individuals with right-brain damage, and five Controls participated in two tasks: (1) matching vocal emblems to photographs ('picture task') and (2) matching vocal emblems to verbal translations ('phrase task'). Cross-group statistical analyses on items on which the Controls performed at ceiling revealed lower accuracy by the group with left-brain damage (than by Controls) on both tasks, and lower accuracy by the group with right-brain damage (than by Controls) on the picture task. Additionally, the group with left-brain damage performed significantly less accurately than the group with right-brain damage on the phrase task only. Findings suggest that comprehension of vocal emblems recruits more left- than right-hemisphere processing.

Lexical retrieval in discourse: an early indicator of Alzheimer's dementia.

We examined the progression of lexical-retrieval deficits in individuals with neuropathologically determined Alzheimer's disease (AD; n = 23) and a comparison group without criteria for AD (n = 24) to determine whether linguistic changes were a significant marker of the disease. Our participants underwent multiple administrations of a neuropsychological battery, with initial administration occurring on average 16 years prior to death. The battery included the Boston Naming Test (BNT), a letter fluency task (FAS) and written description of the Cookie Theft Picture (CTP). Repeated measures analysis revealed that the AD-group showed progressively greater decline in FAS and CTP lexical performance than the comparison group. Cross-sectional time-specific group comparisons indicated that the CTP differentiated performance between the two groups at 7-9 years prior to death and FAS and BNT only at 2-4 years. These results suggest that lexical-retrieval deficits in written discourse serve as an early indicator of AD.

Focusing Our Attention on Socially Responsive Professional Education to Serve Ethnogeriatric Populations With Neurogenic Communication Disorders in the United States.

PURPOSE: This viewpoint discusses a plausible framework to educate future speech-language pathologists (SLPs) as socially responsive practitioners who serve and advocate for the burgeoning vulnerable ethnogeriatric populations with neurogenic communication disorders. METHOD: We provide an overview of the demographic, epidemiological, and biopsychosocial context that supports the implementation of equity-based, population-grounded educational approaches for speech-language pathology services in ethnogeriatric neurorehabilitation caseloads and discuss a plausible perspective based on the educational social determinants of health (SDOH) framework by the National Academies of Sciences, Engineering, and Medicine. RESULTS: The NASEM's three-domain SDOH educational perspective integrates education, community, and organization to create a self-reinforcing pedagogical coproduction that, grounded in the synergized partnerships of educational institutions, engaged communities, and organizational leadership, aims to address systemic drivers of health perpetuating ethnoracial disparities in health, care, and outcomes. CONCLUSION: Exponentially growing vulnerable ethnogeriatric populations with age-related neurogenic communication disorders warrant the implementation of health equity education strategies to train technically prepared, socially conscious SLPs as service providers and advocates.

Effects of language proficiency and language of the environment on aphasia therapy in a multilingual.

We examined the relative proficiency of four languages (Spanish, German, French, English) of a multilingual speaker with aphasia, JM. JM's self-rated proficiency was consistent with his naming accuracy for nouns and verbs (The Object and Action Naming Battery, Druks & Masterson, 2000) and with his performance on selected subtests of the Bilingual Aphasia Test (Paradis & Libben, 1987). Within and between-language changes were measured following two periods of language treatment, one in a highly-proficient language (Spanish) and one in a less-proficient language (English). The various outcome measures differed in their sensitivity to treatment-associated changes. Cross-language treatment effects were linked to the language of the environment at the time of testing and to relative language proficiency.

The contribution of set switching and working memory to sentence processing in older adults.

This study evaluates the involvement of switching skills and working-memory capacity in auditory sentence processing in older adults. The authors examined 241 healthy participants, aged 55 to 88 years, who completed four neuropsychological tasks and two sentence-processing tasks. In addition to age and the expected contribution of working memory, switching ability, as measured by the number of perseverative errors on the Wisconsin Card Sorting Test, emerged as a strong predictor of performance on both sentence-processing tasks. Individuals with both low working-memory spans and more perseverative errors achieved the lowest accuracy scores. These findings are consistent with compensatory accounts of successful performance in older age.

Age-related differences in idiom production in adulthood.

To investigate whether idiom production was vulnerable to age-related difficulties, we asked 40 younger (ages 18-30) and 40 older healthy adults (ages 60-85) to produce idiomatic expressions in a story-completion task. Younger adults produced significantly more correct idiom responses (73%) than did older adults (60%). When older adults generated partially correct responses, they were less likely than younger participants to eventually produce the complete target idiom (old: 32%; young: 70%); first-word cues after initial failure to retrieve an idiom resulted in more correct idioms for older (24%) than younger (15%) participants. Correlations between age and idiom correctness were positive for the young group and negative for the older group, suggesting mastery of familiar idioms continues into adulthood. Within each group, scores on the Boston Naming Test correlated with performance on the idiom task. Findings for retrieving idiomatic expressions are thus similar to those for retrieving lexical items.

Demographic Effects on Longitudinal Semantic Processing, Working Memory, and Cognitive Speed.

OBJECTIVES: To better understand and compare effects of aging and education across domains of language and cognition, we investigated whether (a) these domains show different associations with age and education, (b) these domains show similar patterns of age-related change over time, and (c) education moderates the rate of decline in these domains. METHOD: We analyzed data from 306 older adults aged 55-85 at baseline of whom 116 returned for follow-up 4-8 years later. An exploratory factor analysis identified domains of language and cognition across a range of tasks. A confirmatory factor analysis analyzed cross-sectional associations of age and education with these domains. Subsequently, mixed linear models analyzed longitudinal change as a function of age and moderation by education. RESULTS: We identified 2 language domains, that is, semantic control and semantic memory efficiency, and 2 cognitive domains, that is, working memory and cognitive speed. Older age negatively affected all domains except semantic memory efficiency, and higher education positively affected all domains except cognitive speed at baseline. In language domains, a steeper age-related decline was observed after age 73-74 compared to younger ages, while cognition declined linearly with age. Greater educational attainment did not protect the rate of decline over time in any domain. DISCUSSION: Separate domains show varying effects of age and education at baseline, language versus cognitive domains show dissimilar patterns of age-related change over time, and education does not moderate the rate of decline in these domains. These findings broaden our understanding of age effects on cognitive and language abilities by placing observed age differences in context.

Cross-language lexical connections in the mental lexicon: evidence from a case of trilingual aphasia.

Despite anecdotal data on lexical interference among the languages of multilingual speakers, little research evidence about the lexical connections among multilinguals' languages exists to date. In the present paper, two experiments with a multilingual speaker who had suffered aphasia are reported. The first experiment provides data about inter-language activation during natural conversations; the second experiment examines performance on a word-translation task. Asymmetric patterns of inter-language interference and translation are evident. These patterns are influenced by age of language learning, degree of language recovery and use, and prevalence of shared lexical items. We conclude that whereas age of language learning plays a role in language recovery following aphasia, the degrees of language use prior to the aphasia onset and of shared vocabulary determine the ease with which words are accessed. The findings emphasize the importance of patterns of language use and the relations between the language pair under investigation in understanding lexical connections among languages in bilinguals and multilinguals.

How older adults use cognition in sentence-final word recognition.

This study examined the effects of executive control and working memory on older adults' sentence-final word recognition. The question we addressed was the importance of executive functions to this process and how it is modulated by the predictability of the speech material. To this end, we tested 173 neurologically intact adult native English speakers aged 55-84 years. Participants were given a sentence-final word recognition test in which sentential context was manipulated and sentences were presented in different levels of babble, and multiple tests of executive functioning assessing inhibition, shifting, and efficient access to long-term memory, as well as working memory. Using a generalized linear mixed model, we found that better inhibition was associated with higher accuracy in word recognition, while increased age and greater hearing loss were associated with poorer performance. Findings are discussed in the framework of semantic control and are interpreted as supporting a theoretical view of executive control which emphasizes functional diversity among executive components.

Change in object naming ability during adulthood.

Using longitudinal data on the Boston Naming Test ( Kaplan, Goodglass, & Weintraub, 1983) collected over 20 years from healthy individuals aged 30 to 94, we examined change in lexical retrieval with age, gender, education, and their interactions. We compared results between random-effects longitudinal and traditional cross-sectional models. Random-effects modeling revealed significant linear and quadratic change in lexical retrieval with age; it also showed a Gender x Education interaction, indicating poorest performance for women with less education. Cross-sectional analyses produced greater estimates of change with age than did longitudinal analyses.

Effects of hypertension and diabetes on sentence comprehension in aging.

OBJECTIVES: To assess the impact of hypertension and diabetes mellitus on sentence comprehension in older adults. METHOD: Two hundred and ninety-five adults aged 55 to 84 (52% men) participated in this study. Self-report mail survey combined with medical evaluations were used to determine eligibility. Multiple sources were used to determine whether hypertension and diabetes were present or absent and controlled or uncontrolled. Sentence comprehension was evaluated with two tasks: embedded sentences (ES) and sentences with multiple negatives (MN). Outcome measures were percent accuracy and mean reaction time of correct responses on each task. RESULTS: Regression models adjusted for age, gender, and education showed that the presence of hypertension impaired comprehension on the multiple negatives task (p < .01), whereas the presence of diabetes impaired the comprehension of embedded sentences (p < .05). Uncontrolled diabetes significantly impaired accurate comprehension of sentences with multiple negatives (p < .05). No significant patterns were found for reaction time. DISCUSSION: The presence of hypertension and diabetes adversely affected sentence comprehension, but the relative contribution of each was different. These findings support the researchers' earlier speculations on the neurobiological mechanisms underlying the effects of hypertension and diabetes on language and cognition in aging. Uncontrolled disease status demonstrated more complicated age-related effects on sentence processing, highlighting the clinical importance for cognitive aging of identifying and managing vascular risk factors.

Bilateral brain regions associated with naming in older adults.

To determine structural brain correlates of naming abilities in older adults, we tested 24 individuals aged 56-79 on two confrontation-naming tests (the Boston Naming Test (BNT) and the Action Naming Test (ANT)), then collected from these individuals structural Magnetic-Resonance Imaging (MRI) and Diffusion Tensor Imaging (DTI) data. Overall, several regions showed that greater gray and white matter volume/integrity measures were associated with better task performance. Left peri-Sylvian language regions and their right-hemisphere counterparts, plus left mid-frontal gyrus correlated with accuracy and/or negatively with response time (RT) on the naming tests. Fractional anisotropy maps derived from DTI showed robust positive correlations with ANT accuracy bilaterally in the temporal lobe and in right middle frontal lobe, as well as negative correlations with BNT RT, bilaterally, in the white matter within middle and inferior temporal lobes. We conclude that those older adults with relatively better naming skills can rely on right-hemisphere peri-Sylvian and mid-frontal regions and pathways, in conjunction with left-hemisphere peri-Sylvian and mid-frontal regions, to achieve their success.

Effects of health status on word finding in aging.

OBJECTIVES: To evaluate effects of health status on word-finding difficulty in aging, adjusting for the known contributors of education, sex, and ethnicity. DESIGN: Cross-sectional. SETTING: Community. PARTICIPANTS: Two hundred eighty-four adults aged 55 to 85 (48.6% female) participating in an ongoing longitudinal study of language in aging. MEASUREMENTS: Medical, neurological, and laboratory evaluations to determine health status and presence or absence of hypertension and diabetes mellitus. Lexical retrieval evaluated with the Boston Naming Test (BNT) and Action Naming Test. RESULTS: Unadjusted regression models showed that presence of diabetes mellitus was not related to naming. Presence of hypertension was associated with significantly lower accuracy on both tasks (P<.02). Adjustment for demographics attenuated the effect of hypertension (P<.08). For the BNT, a variable combining presence, treatment, and control of hypertension was marginally significant (P<.10), with subjects with uncontrolled hypertension being least accurate (91.4%). Previously observed findings regarding the effects of age, education, sex, and ethnicity were confirmed. CONCLUSION: In this sample of older adults, hypertension contributed to the word-finding difficulty of normal aging, but diabetes mellitus did not.

Semantic verbal fluency in two contrasting languages.

This cross-linguistic study investigated Semantic Verbal Fluency (SVF) performance in 30 American English-speaking and 30 Finnish-speaking healthy elderly adults with different cultural and linguistic backgrounds. Despite the different backgrounds of the participant groups, remarkable similarities were found between the groups in the overall SVF performance in two semantic categories (animals and clothes), in the proportions of words produced within the first half (30 seconds) of the SVF tasks, and in the variety of words produced for the categories. These similarities emerged despite the difference in the mean length of words produced in the two languages (with Finnish words being significantly longer than English words). The few differences found between the groups concerned the types and frequencies of the 10 most common words generated for the categories. It was concluded that culture and language differences do not contribute significantly to variability in SVF performance in healthy elderly people.